I have a 1992 Chevy S10 truck and i just replaced the starter and it still wont start lights get dim and will not turn over to start?

Probably the battery or alternator. It could also be the starter malfunctioning but it is easier to check the cheapest and most accessible components first. Bring your battery to an NAPA Autoparts or similar and they will check it for free or even charge it up again. If it keep dying on you, then you have a problem with the electrical system. Next up on the list is the alternator. Take off the belt, unbolt the alternator and bring it to NAPA or similar again and they will test if it is broken or not. You can change it right there and bolt on the new one. Worst case your electrical system is shot and there is a fault somewhere in the system. Takes some time to find out the gremlin in the system, if you have the patience and the tools (electrical tester, light, etc...) then you might want to do it yourself. Otherwise, if you have exhausted all the options above, your only two choices are replace the wiring harness, (about 70-200 usd depending on car and maker) or bring it to a shop and ask them to figure it out, but make sure you tell them what you did and checked for so that they wont check over what you already replaced/fixed and waste time and money. Good luck.